If they are plastic, thin tin or alum even small bears can/will chew them up. Last fall I put out a large heavy plastic barrel...I know better but it was all we had left in camp and they were robbing the log roll blind and we were just feeding the forest..anyhew it lasted only a few days the scat, paw and teeth markes indicated mostly small bears where coming in. Now if reasonably solid the only concern would be volume cap. (meaning how much bait they'll hold between your visits) and can you chain them to a tree. If not they tend to roll it away on yeah and weight seems to have little bearing they are powerful little critters. My baits quite often I have to unravel them as the bears try to roll them off but being tethered just end up shorting the chain length

. They also dent the crap out of them once the volume of the bait goes down, these are 45 gal steel drums!
As to hole size IME & O while you don't want them to gorge all your bait with ease, you still need to feed them. Make sure that they will have a large enough diameter hole to spoon with the paw, snout and tongue...by your description they sound ok in this manner. We have tried on further hunting locals where we could only bait weekly smaller holes (2" or so) and the baits were not nearly as effective. The only way to ensure that lid will stay on and not be dragged off or destroyed is bolt/clamp/whatever is required to make it so only you and tools will get off. Most my barrels are the ones with the ring/bolt to ensure the barrel/lid stay intact but I have also fashioned a few with a piece of angle iron, decent sized nuts and bolts. Just weld the angle iron the nuts in a couple of spots and thread on a bolt..shes now bolted down and ensure your lid stays put.
Again this is just my opinion but if light duty or unchained you may come back to find destroyed/barrels gone or if they can't eat they may be or become on the cool side. If given the choice between a barrel that'll maybe last a few days on hot bait site or log roll pit, I'd stick to log roll pit!
Best of luck